Modeling the Electron Flux Enhancement and Butterfly Pitch Angle Distributions on L Shells <2.5
Abstract
We analyze an energetic electron flux enhancement event in the inner radiation belt observed by Van Allen Probes during an intense geomagnetic storm. The energetic electron flux at L~1.5 increased by a factor of 3 with pronounced butterfly pitch angle distributions (PADs). Using a three‐dimensional radiation belt model, we simulate the electron evolution under the impact of radial diffusion, local wave‐particle interactions including hiss, very low frequency transmitters, and magnetosonic waves, as well as Coulomb scattering. Consistency between observation and simulation suggests that inward radial diffusion plays a dominant role in accelerating electrons up to 900 keV and transporting the butterfly PADs from higher L shells to form the butterfly PADs at L~1.5. However, local wave‐particle interactions also contribute to drive butterfly PADs at L ≳ 1.9. Our study provides a feasible mechanism to explain the electron flux enhancement in the inner belt and the persistent presence of the butterfly PADs at L~1.5.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 28, 2019
- Source ID
- 10.1029/2019gl084822
Entities
People
- Binbin Ni
- Haimeng Li
- Man Hua
- Qianli Ma
- Wen Li
- Xiaochen Shen
- Yukitoshi Nishimura
Organizations
- Air Force Office of Scientific Research
- Boston University
- Nanchang University
- National Natural Science Foundation of China
- National Science Foundation
- University of California, Los Angeles
- Wuhan University